What's the rationale for this suggestion?

# intellij

[bod]

What's the rationale for this suggestion?

[ephemient]

similar to the suggestion for updating class to data class I guess

[bod]

similar to the suggestion for updating class to data class I guess

I don't get such suggestion. It seems the object one is related to the fact that it's inside a sealed interface

[Klitos Kyriacou]

Perhaps it's related to this recent discussion. Sealed objects are often used in exhaustive when clauses, but if the object comes from Java serialization, or from a mocking framework, the object may not be an actual singleton and the == operator used by the when clause may return false even for objects of the same type. Making it a data object fixes this possibility.

[bod]

hmm interesting!

[Casey Brooks]

Also, the default toString() of a non-data object is platform-dependent while toString() of a data class is not. This can be problematic in KMP apps for things like logging, when the platform’s representation doesn’t include any type information.

For example, see how the toString() here changes between JVM and JS targets (and how completely useless the JS version is) https://pl.kotl.in/OZ8JtYfeC

[bod]

I'm now wondering why data object exists and object is not doing "the right thing" by default 🙂 But I suppose I'm not seeing the full picture (maybe that would be a breaking change...)

[Casey Brooks]

Many top-level objects don’t need all the extra stuff generated by the data object, and it would increase the binary size significantly to make them all data objects. A normal object is simple a singleton class with no extra ceremony. It’s just that the common semantics of an object inside a sealed class is closer to that of a data class that doesn’t have members, rather than an actual singleton, hence the addition of data object and its Intellij inspection

[bod]

that makes a lot of sense! Thanks 🙏